front cross lever, great for navigating through tight spaces while on the tops of the bars. Remember that as you get more comfortable riding fixed, you will be able to control your momentum using backpressure throughout the pedal stoke at low to moderate speeds more effectively (good for snaking your way through crowds), negating the use of your brakes.
The drawback of this lever position is that when you're REALLY booking it (in the drops), you gotta move your hands from the drops to the tops quickly should an "OH SH*T!" moment arise...